No abstract

Inhibitors of the Hedgehog (Hh) pathway transducer Smoothened (Smo) have been approved for cancer treatment, but Smo mutations often lead to tumor resistance and it remains unclear how Smo is regulated. In this study, we identified the small GTPase Arl13b as a novel partner and regulator of Smo. Arl13b regulated Smo stability, trafficking and localization which are each crucial for Hh signaling. In gastric cancer cells, Arl13b stimulated proliferation, migration and invasion in vitro and in vivo. In clinical specimens of gastric cancer, Arl13b expression correlated strongly with tumor size and depth of invasion; patients with high levels of Arl13b had a poor prognosis. Our results show how Arl13b participates in Hh pathway activation in gastric cancer.

No abstract

To detect the expression of miRNA-214 in human gastric cancer cell lines of BGC823, MKN45 and SGC7901, and to identify the effect of miRNA-214 on cell cycle and apoptosis of these cells. Expression of miRNA-214 in human normal gastric mucosal cell line GES-1 and human gastric cancer cell lines was detected by real-time reverse-transcription polymerase chain reaction. Antisense-miRNA-214 oligonucleotides were transfected transiently into gastric cancer cell lines to down-regulate the expression of miRNA-214. The cell cycle and apoptosis were studied by flow cytometry assay. PTEN, one of the target genes of miRNA-214 was detected by using of immunocytochemistry and Western blotting. MiRNA-214 was overexpressed in gastric cancer cell lines of BGC823, MKN45 and SGC7901 compared with normal gastric mucosal cell line GES-1. Antisense-miRNA-214 oligonucleotides significantly down-regulated the expression of miRNA-214, and increased the portion of G1-phase and decreased the portion of S-phase in BGC823 and MKN45 cells. The immunocytochemistry test and Western blotting analysis showed that the down-regulation of miRNA-214 could significantly up-regulate the expression of PTEN in BGC823 and MKN45 cells. MiRNA-214 is overexpressed in human gastric cancer cell lines of BGC823, MKN45 and SGC7901. The down-regulation of miRNA-214 could induce a G1 cell cycle arrest in them, the up-regulation of PTEN maybe one of the mechanism.

Meningiomas are common types of adult nerve system tumors. Although most cases are considered benign, due to its high rate of recurrence and easy malignant progression to anaplastic meningioma they present a puzzle for the current treatment. The HER-2 oncogene has important value for meningioma cells development and progression. So far, little is known about the effect on the exact underlying signal pathway and molecular mechanisms of HER-2-positive meningioma cells. The goal of the present study was to determine the effects of HER-2 gene and possible involvement of MAPK signal pathway in human malignant meningioma. We applied q-PCR analysis, immunofluorescence (IF) staining, western blot analysis, animal model, MAPK inhibition, MTT assay and cell invasion analysis for the investigation. The results demonstrated that the downregulation of the expression of HER-2 significantly inhibited cell motility and proliferation of human meningioma cells in vivo. Accordingly, in the HER-2-overexpression meningioma cells with the inhibition of ERK1/2, ERK5, JNK, in the cells with the ERK1/2, ERK5 inhibition, protein expression was markedly suppressed as well as the cell proliferation resistance. No difference was observed in the HER-2-overexpression meningioma cells with the inhibition of JNK. These findings suggest that HER-2 gene can affect the proliferation ability of human meningioma cells in vivo and MAPK signal pathway may contribute to the carcinogenesis and development of human meningiomas combinating with HER-2.